Liquid fuel injection apparatus



Jun e 4, 1946. R. MILLER LIQUID FUEL INJECTION APPARATUS Filed April 26, 1944 INVENTOR fialfuh Mi/ ler BY KAT}! NEY Patented June 4, 1948 UNITED STATES PATENT onion 7 mourn nfr ztrrzn Arrm'rus I 4 lpp fizfizlzrz 532,918

appear from the following description, the accompanying drawing and the appended claims.

I Referring to the drawing forming a part of this application, Figure l is a vertical central sectional view of an injector nozzle and metering valve unitary structure, part being shown in full. and a source of fuel being shown diagrammaticall .and Fig. 2 is a section on the line II-II of Fig. 1, parts being shown in full and parts being broken away.

The fuel injection apparatus shown in Fig. 1, indicated generally by the reference numeral I,

has three parts, the parts being a source of fuel supply 2, av metering valve 3 and an injector nozzle 4, the valve 3 and nozzle 4 being secured together and having common parts, thereby forming a unit injector. Apparatus l is for employment in internal combustion engines having an overhead cam shaft mechanism (not shown) as will presently appear. lv

Metering valve 3 includes a hollow body which has at its top a central chamber 6, therebelow another chamber I of lesser. diameter than chamber 6 and thereblow an axial bore providing a cylinder 8 of lesser diameter than chamber 1, there being a shoulder 9 between chambers 6 and I and a shoulder I0 between chamber I and cylinder 3. The bottom portion of body 5 is externally threaded. The metering valve further includes a casing ll having internal threads screwed on the bottom portion of body 5. Casing II has an axial bore 12 below the bottom edge of body 6 and an inwardly extending annular shoulder I3 at the bottom of bore I2.

A valve element I4 is disposed in cylinder 8, chamber '1 and chamber 6. A washer I5 is secured to'the upper end of element 14 by a split snap ring I6, and washer l5 supports a crosshead or sleeve H, which engages the top of element l4 and is adaptedto reciprocate in chamber 6 and to be acted upon by a rocker arm of the overhead cam shaft mechanism aforementioned. A washer I8 is supported on shoulder 9,

- fitting freely around element 14, and a coil spring I9 is compressed between washer l6 and I3,

shaft mechanism in a well-known manner.

Metering valve 3 further includes an adjusting mechanism. indicated generally by the reference numeral 26, which is of well-known'construc tion'and therefore it is not fully shown and will be but briefly described. Mechanism 2!! includes a gear 2| having upwardly extending spaced lugs 22. Gear 2i is supported on shoulder ill and fits freely around element I4. Guides 23 formed integrally with the element l4 slide in the guideways formed by the lugs 22. A rack 24 meshes wtih gear 2 I.

Element M has a cylindrical port-controlling part 25 for controlling ports presently to be dedescribed. Part 25 includes reduced portion 26 and 21, shoulders 28 and 23 at opposite ends of portion 26, .and shoulders 36 and 3| at opposite ends of portion 21. Portions 26 and 21 are spaced from the wall of cylinder 6 providing chambers 32 and 33 respectively. There is furtheran axial bore 34 extending from the bottom face -of-element l4 to the reduced portion 26 and opening into the chamber 32 by means of a radial bore 35. The bottom face of'element I4 isf paced from the bottom of the body 6 providing a chamber 36 into which bore 34 opens at it lower end.

Shoulders 23 and 30 are inclined and zig-zag as is clearly shown in Fig. 2, this being a well-known pump or metering valve contour for use on adjustable pump or valve elements.

Nozzle 4 is a composite structure and includes a body 31 having a portion disposed in bore l2 and restingon shoulder l3, theremainder of the body.3| extending through the open end of casing' ll surrounded by shoulder I3 and therebeyond. A washer or spacer 33'is disposed in bore 12 on top of the body 31, and a housing 33 is.

disposed in bore l2 between spacer 313 and the .bottom of the body 5. Body 31 has jets 40 in its lower end adapted to open into a cylinder of an internal combustion engine (not shown), a bore 4| communicating with the Jets, 9. port or valve seat 42 at the upper end of the bore 4|, an injection fuel chamber 43 above the valve seat, a passage 44 leading from chamber 43 to the upper face of the body 31, and an axial bore pro viding-a cylinder 45 opening at its bottom into chamber 43 and at its top through the top face of the body 31.

A needle valve 46 is disposed'in cylinder 46 and chamber 43, and is supported on seat 42 for coaction therewith.. A plunger 41 integral with I appear.

pressure fuel tank (not shown).

1 ber 20, 1942.

The operation of the apparatus as thus far vend by means of a conical valve seat 58 with cylinder 45. Seat 88 at its bottom edge is of a larger diameter than cylinder 48. Chamber 48,

bores 49 and seat 58 provide a loading fuel chamber for plunger 41, a will-presently more fully A stem 8|, integral with plunger 41, extends upwardly therefrom through seat 58 and bore 49 into chamber 48, there being clearance around the stem 8| for passage of fuel thereby.

, A spring seat 82 is supported ontop of stem Stem 5| is of smaller diameter than plunger 41, thereby providing a shoulder 88. The top edge of plunger 41 acts as a valve coacting with seat 88, as will presently appear. A coil spring 84 is disposed in chamber 48 and compressed between the seat 52 and the top wall of chamber 48, acting to force plunger 41 downward. A dowel 85 sedescribed is as follows: Fuel'under pressure from p the source of fuel supply 2 passes through pascures body.81, spacer 88 and housing 89 against relative rotation, and another dowel 85" (Fig. 2) secures body 5 and-housing 88 against relative rotation.

A passage 58 extends longitudinally throughhousing 88 and communicates with passage 44 through a passage 81 formed in spacer 88. A passage 88 is formed in the wall of body 8, 'opening at its upper end through the side wall thereof near the bottom of chamber 1, and extending downwardly through the body to a point adjacent chamber 88, where it is branched, a branch 88 opening into chamber 88, and a branch 88'extending downwardly and communicating with passage 88. Passage 88 is connected at its upper end by a pipe 8| to the source of fuel supply 2 which may be any conventional apparatus adapted to supply fuel under constant pressure to pipe 8|.- For example, the source 2may be a pump drawing fuel from a fueltank (not shown) and pumping it through pipe 8|, the pump being provided-with means (not shown) for regulating the delivery pressure. It is contemplated that there will be a metering-valve injector nozzle unit for each cylinder of the engine and that the source 2 will provide fuel for .all the units of the engine. In such case pipe 8| will be a header, with branches for each of the units.

A passage 82 is formed in the wall of body 8, connecting chamber 82 to the exterior below rack 24. An annular groove 88 1s formed in the body 8 around cylinder 8, forming part of passage 82,

the cam shaft rocker arm mechanism (not the passage 82 extending from the groove 88 at munication with the source. Passage 88 is in continuous communication with the source and with branches 88 and 88, passages 88, 81 and 44. and chamber 48. Thus fuel under constant pressure is continuously present in chamber 48, .for injection and for exerting a lifting force on plunger 41. Branch 89 opens continuously into chamber 88 which therefore isin continuous communication with the source of fuel supply 2.

Element I4 is shown in Fig. I adjusted for under pressure in the chamber 48, and because.

the spring 84 augments this closing pressure.

Further downward movement of element H by shown) acting on sleeve l1, effects closing of branch 88 simultaneously with opening of branch 81 to chamber 8.2. Pressure in chamber 48 is thereby reduced as it is connected to the low pressure tank by means of passages 88 and 84, branch 81, chamber 82, and passage 82. Pressure in chamber 48 then lifts plunger 41 so' that its shoulder 88 engages, at its periphery, conical seat 88, and effects injection, which continues until the cam shaft mechanism permits element M to rise, due to the action of spring l8, to-a position opening branch 88 to chamber 88', whereupon fuel again loads plunger 41, closing valve 48. The conical seat 88 leaves the entire surface of the shoulder 88 available for the action of the loading pressure. During downward movement of element l4, the chamber 88 below element 1-4 is vented, preventing pressure rise therein,

through bores 84 and 88, chamber 82 and passage 82.

The operation of the apparatus as thus far described is substantially the same as the operation of the apparatus of my aforementioned pending application, to which reference may be had for further understanding of theconstrucsage 88, which is the only passage in direct com- 7 tion and operation of the apparatus of the present invention.

The apparatus of the present invention further includes, as an added feature of the appa- 84, communicating at its lower end with chamber 48 through a passage 88 formed in housing 88, and having a branch 88 at its upper portion adapted to open into chamber 88 and a branch 88 81 thereabove adapted to open into chamber 82. Branches 88 and 81 extend around the element l4, and have diametrically opposite portions opening into the cylinder 8 for balancing transverse oil pressure forces on the element I4.

The apparatus as thus far described is substantially the same a the apparatus of my oopending application Serial No. 482,873, filed Octoratus of my aforesaid pending application, means for cooling the tip of 'nozzle body 81 so that it is not excessively heated by the heat of combustion in the engine cylinder when the bore 4| is closed. This means is formed by a cooling fuel passage 88' adapted to connect and disconnect chamber 48 respectively with and from passage 82, chamber 48 being connected to passage "82 between injections. The cooling fuel passage is disposed degreesfrom the injection fuel passage and is shown in Fig. 2 as including a passage 88 in the nozzle body 81, .a passage 18 in the spacer 88, a passage 1| in the housing 88 and a passage 12 in the body 8. Passage 12 opens into cylinder 8 just below shoulder 28 when the valve element is at its full uppermost position (above it position shown in Fig. 2). Thus, at this time, the cooling fuel passage 88 opens into chamber 32 and is connected to passage 82 and therefore to the fuel tank.

The operation of the nozzle cooling feature of this invention is as follows: When the valve element It is at its uppermost position, the cooling fuel oil continuously flows from the source of fuel supply 2 through the injection fuel passage to the chamber 43 and therefrom through the cooling fuel passage 68 back to the fuel tank.

Thus a continuous flow of cooling oil i flowing through the chamber 43, cooling the tip of the nozzle at this time. when element ll starts to move downward, passage 88 is closed by the pork chamber 32 and cooling fuel again flows through.

passage is from chamber 43 to the tank. Thus a substantially continuous flow through the chamber 43 for cooling the nozzle tip is effected, there being a substantially continuous flow of cooling fuel from source 2 either through the nozzle jets when the valve is open or through the cooling fuel passage is when the valve is closed. a

While the cooling feature has been shown in v a unit injector bpe of apparatus for use in overhead cam shaft engines, it is equally adapted for connecting said loading chamber through said cylinder with said source for supply of fuel to said loading chamber at source pressure and further connecting said loading chamber through said cylinder with said exterior, said injector further having a valve element in said. cylinder for controlling said passagewa means a passing therethrough to effect pressure differentials in said chambers, and a valve element in said bore for controlling said port in response to said pressure differentials in said chambers, said cylinder valve element closing and opening said injection chamber respectively from and to said exterior throughout the entire periods that said port isrespectively open and closed whereby said tip is continuously cooled by an uninterrupted flow of pressure fuel through said injection chamber from said source at said source pressure,

2. A liquid fuel injection apparatus comprisin a casing having a nozzle tip, said tip being provided with an injection port and an injection fuel chamber adjacent and communicating with said port, said casing-further having a loading fuel chamber and a tip-cooling passage open at one end to said injectionchamber and open at the other end to the exterior of said casing for flow of fuel therethrough from said injection chamber to said exterior; a source of pressure fuel supply connected to said chambers for supply of fuel from said source to said loading chamberat source pressure and for continuous supply of fuel from said sourceto said injection chamher at source pressure; an injection valve inother types of apparatus for use in other types of,

internal combustion engines.

While there has been hereinbefore described an approved embodiment of the invention, it will be understood that many and various changes and modifications in form, arrangement of parts and details of construction thereof may be made without departing from the spirit of the invention, and that all such changes and modifications as fall within the scope of the appended claims are contemplated as a part of this invention.

The invention claimed and desired to be secured by Letters Patent is:

1. A liquid fuel injection apparatus comprising a source of pressure fuel supply: and an injector eluding a bore in said casing between and opening to said chambers and having a piston-valve element in said bore operably subjectable to fuel pressures in said chambers for controlling said port; a spring loading saidelement: a valve ineluding a cylinder in said casing and a reciprocable mechanically-actuated member in said cylinder including a valve element for controllin said passage and an adjustable metering-valve element for controlling supply of and release of pressure fuel to and from said loading chamber effective respectively in the closing and openin of said injection valve, said member elements reciprocating in unison with said member; and means for adjusting said metering-valve element, said spring and said chamber pressures Op rat said piston-valve element to control said port,

' said passage-control-valve element being closed,

having a casing provided with a nozzle tip, said tip having an injection port and an injection fuel chamber-adjacent and communicating with said-port, said casing further having a loading fuel chamber, a valve bore connecting said chambers, passageway means connecting said source with said injection chamber for continuous supply of fuel thereto at source pressure, and a valve cylinder, said passageway means further connectme said injection chamber through said cylinder with the exterior of said injector, and further closing said passage from said exterior, throughout the injection valve open period and being open, opening said passage to said exterior, substantially throughout the injection valve closed period whereby said tip is continuously; cooled by a substantially uninterrupted flow of pressure fuel through said injection chamber from said source at said source pressure.

I RALPH BELIEF... 

